The present invention relates to a substrate processing apparatus that subjects substrates to processing.
Substrate processing apparatuses are used to subject various types of substrates such as semiconductor substrates, substrates for liquid crystal displays, plasma displays, optical disks, magnetic disks, magneto-optical disks, and photomasks, and other substrates to various types of processing.
Such a substrate processing apparatus generally subjects a single substrate to a plurality of different types of processing successively (see, for example, JP 2003-324139). The substrate processing apparatus as described in JP 2003-324139 includes an indexer block, an anti-reflection film processing block, a resist film processing block, a development processing block, and an interface block. An exposure device is arranged adjacent to the interface block as an external device separate from the substrate processing apparatus.
In the above-mentioned substrate processing apparatus, a substrate carried out of the indexer block is transported to the exposure device through the interface block after being subjected to anti-reflection film formation and resist film coating processing in the anti-reflection film processing block and the resist film processing block. After a resist film on the substrate is subjected to exposure processing in the exposure device, the substrate is transported to the development processing block through the interface block. After the resist film on the substrate is subjected to development processing to form a resist pattern thereon in the development processing block, the substrate is transported to the indexer block.
With recent increases in density and integration of devices, making finer resist patterns has become an important problem. Conventional exposure devices have generally performed exposure processing by reduction-projecting reticle patterns on substrates through projection lenses. With such conventional exposure devices, however, the line widths of exposure patterns are determined by the wavelengths of light sources of the exposure devices. Therefore, making finer resist patterns have had limitations.
Therefore, a liquid immersion method is suggested as a projection exposure method allowing for finer exposure patterns (see, for example, WO99/49504 pamphlet). In a projection exposure device according to the WO99/49504 pamphlet, an area between a projection optical system and a substrate is filled with a liquid, resulting in a shorter wavelength of exposure light on a top surface of the substrate. This allows for finer exposure patterns.
When the substrate is subjected to the exposure processing by means of the liquid immersion method disclosed in the above-mentioned WO99/49504 pamphlet, however, a contaminant that adheres to a back surface of the substrate is mixed into the liquid within the exposure device if the back surface of the substrate is contaminated. Thus, a lens of the exposure device is contaminated, resulting in a defective dimension and a defective shape of an exposure pattern.
Furthermore, when the substrate after the exposure processing is carried out of the exposure device, and the back surface of the substrate carried into a development processing block is contaminated, development problems may occur. Thus, there is a need in the art for improved methods and systems for substrate processing.